Volvo Repair: drive train, volvo 740, drive train

Question
i have a 1989 volvo 740
it has an automatic tranny
yesterday it washaving trouble shifting and it would not let me go more than 15 mph
today i drove it and now it will not go over 35mph
would over filling the fluids
or a clogged filter cause this problem  

Answer
Hello,
you wrote that "having trouble shifting", so, the problem is "transmission", get it checked, unfortunately I should say that it may need to be replaced with new one. I hope you can find a repairer for it and it can be repaired.
Regards//Vedat...